JP2008205833A - Digital camera and control method thereof - Google Patents

Abstract

An original performance is sufficiently exhibited when an AC adapter is used.
A power source type discriminating unit includes a secondary battery, a DC jack, a resistor, a switch circuit, a charge control circuit, a voltage detection circuit, and a CPU. When the switch circuit 29 is turned on by pressing the power button 16 and the AC adapter 23 is connected to the DC jack 22, the power from the AC adapter 23 is supplied to the power circuit 32. The voltage detection circuit 31 detects the power supply voltage applied from the AC adapter 23 to the charge control circuit 30 and sends it to the CPU 35. The CPU 35 determines that the power source is the AC adapter 23, and performs initial setting in the power-up mode. The operation clock of the imaging unit 26 is set to 36 MHz, the vertical number of through image readout from the CCD 38 is set to 320, and the imaging frame rate of the CCD 38 is set to 60 fps. As a result, a through image with high resolution and smooth movement is displayed on the LCD 17.
[Selection] Figure 2

Description

  The present invention relates to a digital camera and a control method thereof, and more particularly to a digital camera capable of using a plurality of types of power supplies and a control method thereof.

  A digital camera that converts an optical image into an electrical signal using an image pickup device such as a CCD or a CMOS image sensor and stores it as a digital image data in a storage medium such as a memory card has become widespread.

  In a digital camera, either a primary battery such as an AA battery or a secondary battery such as a rechargeable lithium ion battery is generally used as a power source for driving, but it can receive power from an AC adapter. There is also.

  Such a digital camera capable of using a plurality of types of power supplies discriminates the type of connected power supply and performs drive control according to the type of power supply. For example, in the camera-integrated VTR described in Patent Document 1, when the power supply system determination unit detects a battery, the display system switching unit is set to the power saving mode. When the power supply system determination unit detects the AC adapter, the normal mode is set. In the power saving mode, only one of the finder unit and the liquid crystal panel unit is turned on. In the normal mode, the finder unit is turned on, and the ON / OFF state of the liquid crystal panel unit is switched according to the situation.

  The imaging system described in Patent Document 2 uses a secondary battery pack or a charging device. When a secondary battery pack is mounted as a power source, this is detected by the power source detection means and controlled to reduce the brightness of the backlight unit of the display unit, thereby reducing the power consumption in the display unit.

  In the electronic still camera described in Patent Document 3, in order to reduce power consumption, the drive frequency of the image sensor is lowered and the drive voltage required for reading is lowered.

  When the notebook computer described in Patent Document 4 is switched from AC drive to battery drive, the display brightness is reduced to save battery power. At this time, the decrease in the display brightness is moderately noticed by the user. To do.

The digital camera described in Patent Document 5 detects whether a battery or a power source from an AC power source is used as a power source by a power source detection circuit, and the battery used when the battery is used as a power source Detects whether the battery is a dedicated battery, performs power supply control to the display unit, and performs power supply control to the character liquid crystal display device.
Japanese Patent Application No. 11-0666828 JP-A-11-146254 JP 2003-153093 A JP 2001-184046 A JP 2001-230960 A

  The above Patent Documents 1 to 5 all disclose how to reduce power consumption when using a battery, but positively how to drive when an AC adapter is connected. There is no description. In digital cameras that mainly use batteries, if the power is turned on with the batteries loaded, the power-saving initial settings will be performed, and even if an AC adapter is connected later, the through image will move smoothly. In some cases, the original performance of a digital camera cannot be fully exhibited.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a digital camera and a control method thereof that can sufficiently exhibit the original performance rather than power saving when using an AC adapter. .

  In order to solve the above problems, a digital camera according to the present invention includes an image sensor that photoelectrically converts a subject image formed by a photographing optical system and outputs an image signal, and whether a power source is a battery or an AC adapter. A power source type discriminating unit for discriminating, and when the power source type discriminating unit discriminates that the power source is an AC adapter, the frame rate of the imaging signal output from the imaging device and And / or a controller that increases the number of vertical lines.

  The control unit increases the operation clock of the image sensor when the power source type determining unit determines that the power source is an AC adapter, compared to when the power source is a battery.

  When the power source type discriminating unit determines that the power source is an AC adapter, the control unit is configured to display a backlight of a liquid crystal display that displays an image based on the imaging signal, rather than when the power source is a battery. It is characterized by increasing the brightness.

  The power source type discriminating unit discriminates whether the power source type is a primary battery, a secondary battery, or an AC adapter, and prohibits charging in the case of a primary battery, and uses a charging control circuit in the case of a secondary battery. It is characterized by managing charge control.

  According to the digital camera control method of the present invention, the power source type determining step for determining whether the power source is a battery or an AC adapter, and the power source is a battery when the power source is determined to be an AC adapter. Rather than a control step for increasing the frame rate and / or the vertical number of the imaging signal output from the imaging device.

  The control step includes increasing the operation clock of the image sensor when the power source type determining unit determines that the power source is an AC adapter, compared to when the power source is a battery. To do.

  In the control step, when the power supply type determination unit determines that the power supply is an AC adapter, the brightness of the backlight of the liquid crystal display that displays an image based on the imaging signal is higher than when the power supply is a battery. It is characterized by including raising.

  According to the digital camera and its control method of the present invention, it is determined whether the power source is a battery or an AC adapter, and when it is determined that the power source is an AC adapter, imaging is performed more than when the power source is a battery. Since the frame rate and / or the vertical number of the imaging signal output from the element is increased, the original performance can be sufficiently exhibited when the AC adapter is used.

  When the power source is an AC adapter, the operation clock of the imaging device is increased as compared with the case of a battery, so that the original performance can be sufficiently exhibited when the AC adapter is used.

  When the power supply is an AC adapter, the luminance of the backlight of the liquid crystal display is made higher than that of a battery, so that the original performance can be sufficiently exhibited when the AC adapter is used.

  It is determined whether the power source is a primary battery, a secondary battery, or an AC adapter, and charging is prohibited in the case of a primary battery, and charging control is managed in the case of a secondary battery, so an AC adapter is used. In this case, the original performance can be sufficiently exhibited, and even when the power source is a primary battery or a secondary battery, it can be used without any problem.

  The digital camera 10 according to the embodiment of the present invention detects whether the power source is a secondary battery or an AC adapter, and when the power source is an AC adapter, the digital camera 10 can sufficiently exhibit the original performance rather than power saving. Is. As is well known, the AC adapter is used by connecting to a power outlet, and converts commercial AC power supplied from the power outlet into direct current and outputs the direct current.

  As shown in FIG. 1, a retractable photographing lens 12 and a strobe light emitting unit 14 are provided on the front surface of the camera body 11 of the digital camera 10. A shutter button 15 and a power button 16 are provided on the upper surface of the camera body 11.

  On the rear surface (not shown) of the camera body 11, there is an LCD 17 (see FIG. 2) that displays a through image and is used as an electronic viewfinder, and an operation unit 18 (see FIG. 2) configured with a plurality of buttons. Is provided. The LCD 17 also displays a preview image of the captured image and a reproduced image read from the memory card.

  A battery cover 19 is provided on the lower surface of the camera body 11. A rechargeable secondary battery (for example, a lithium battery) serving as a power supply when the digital camera 10 is carried is provided in a battery chamber exposed by opening the battery cover 19. An ion battery 20 (see FIG. 2) is detachably loaded into the camera body 11. Note that the secondary battery 20 may be incorporated in the camera body 11 so as not to be detachable.

  A DC jack 22 is provided on the side surface of the camera body 11. The plug 23 a of the AC adapter 23 is inserted into the DC jack 22. The AC adapter 23 includes a plug 23a, an AC adapter main body 23b, and a cable 23c for connecting them.

  As shown in FIG. 2, the main electrical configuration of the digital camera 10 includes a power supply type determination unit 25, an imaging unit 26, and a control unit 27. The power supply type determination unit 25 includes a secondary battery 20, a DC jack 22, a resistor 28, a switch circuit 29, a charge control circuit 30, a voltage detection circuit 31, and a CPU 35.

  A power supply circuit 32 is connected to the switch circuit 29. When the switch circuit 29 is turned on, the power supply circuit 32 boosts and lowers the power supply voltage from the secondary battery 20 or the AC adapter 23 according to each part of the digital camera 10 and supplies it to each part.

  The DC jack 22 includes three terminals 22 a, 22 b, and 22 c, and the terminal 22 a is connected to the switch circuit 29 and the charge control circuit 30. The terminal 22 b is connected to one end of the resistor 28, the charge control circuit 30, and one end of the secondary battery 20. The terminal 22c is connected to the other end of the resistor 28 and grounded. The switch circuit 29 is turned on / off by the CPU 35 of the control unit 27 that has received the pressing operation of the power button 16.

  When the plug 23 a is not inserted into the DC jack 22, the terminals 22 b and 22 c are short-circuited, so that one end of the secondary battery 20 is grounded, and the other end of the secondary battery 20 is the charging control circuit 30. To the switch circuit 29. When the switch circuit 29 is turned on in this state, the power from the secondary battery 20 is supplied to the power circuit 32, and the power adjusted by the power circuit 32 is supplied to each part of the digital camera 10.

  The voltage detection circuit 31 measures the power supply voltage from the secondary battery 20 that passes through the charge control circuit 30 and sends it to the CPU 35. Since the power supply voltage from the secondary battery 20 is lower than the power supply voltage of the AC adapter, the CPU 35 determines that the power supply is the secondary battery 20.

  Further, the CPU 35 compares the measured voltage A (v) input from the voltage detection circuit 31 with a predetermined threshold voltage α (v), and determines whether A ≧ α. The threshold voltage α is a voltage at which the secondary battery 20 is almost fully charged. The CPU 35 performs initial setting in the same power-up mode as when the AC adapter 23 is connected when A ≧ α, and performs initial setting in the power saving mode when A <α.

  In the power saving mode, when displaying a through image, the operation clock of the imaging unit 26 is 12 MHz, the number of vertical images read out from the CCD 38 (see FIG. 2) of the imaging unit 26 is 160, and the through image is read from the CCD 38. A certain imaging frame rate is 30 fps. Further, the brightness of the backlight of the LCD 17 (see FIG. 2) is shifted to the low luminance side, and the LCD 17 is turned off, etc., when it remains unused for a predetermined time (for example, 3 minutes).

  When the plug 23 a is inserted into the DC jack 22, the short circuit between the terminals 22 b and 22 c is released, so that the negative terminal of the plug 23 a is grounded and connected to the negative terminal of the secondary battery 20 through the resistor 28. Then, the positive terminal of the plug 23 a is connected to the switch circuit 29 and the charge control circuit 30. In this state, when the switch circuit 29 is off, the charge control circuit 30 is driven by the power supply from the AC adapter 23 and the secondary battery 20 is charged.

  When the switch circuit 29 is on, the power from the AC adapter 23 is supplied to the power circuit 32, and the power adjusted by the power circuit 32 is supplied to each part of the digital camera 10. At this time, although the amount of power supplied from the AC adapter 23 to the charge control circuit 30 decreases, the power is supplied from the AC adapter 23 to the charge control circuit 30, so that the voltage detection circuit 31 detects this voltage and the CPU 35 Send to.

  The CPU 35 determines that the power source is the AC adapter 23 based on the voltage input from the voltage detection circuit 31, and performs initial setting in a power-up mode in which the performance of the digital camera 10 is fully exhibited.

  In the power-up mode, at the time of live view display, the operation clock of the imaging unit 26 is the same as that at the time of moving images, 36 MHz, and the number of live view readouts from the CCD 38 (see FIG. 2) of the image pickup unit 26 is the same as that at the time of moving images. The imaging frame rate, which is the speed at which a through image is read from the CCD 38, is set to 60 fps, which is twice the general 30 fps. Further, the brightness of the backlight of the LCD 17 (see FIG. 2) is shifted to the high luminance side, and the power supply auto-off operation of the LCD 17 is not performed.

  If the vertical number of live view readout from the CCD 38 is set to 320, the vertical number of conventional live view readout is 160, so the vertical resolution of the live view is doubled. The image quality is improved.

  When the imaging frame rate of the CCD 38 is set to 60 fps, the display frame rate of the through image displayed on the LCD 17 is also the same 60 fps, so that the movement of the through image becomes very smooth. Since the LCD 17 has a refresh rate higher than 60 Hz, for example, 70 Hz, the through image display at a frame rate of 60 fps in the power-up mode can be performed without any problem.

  The imaging unit 26 includes a photographing lens 12, a CCD 38, an AFE (analog front end) 40, a motor driving unit 41, a CCD driver 42, and a TG (timing generator) 43. In addition to the CCD, a CMOS image sensor can be used as the image sensor.

  The photographing lens 12 incorporates a zoom mechanism, a focus mechanism, and a diaphragm device. The zoom mechanism performs zooming by moving the variable magnification lens constituting the photographing lens 12 in response to the zoom operation of the operation unit 18. The focus mechanism moves the focus lens to perform focusing. The diaphragm device adjusts the light intensity of the subject light incident on the CCD 38 by adjusting the diaphragm. The zoom mechanism, the focus mechanism, and the diaphragm device are each driven by the motor drive unit 41 based on a command from the CPU 35.

  The CCD 38 is disposed behind the photographing lens 12, and subject light transmitted through the photographing lens 12 is incident on the light receiving surface of the CCD 38. The CCD 38 is provided with a large number of light receiving portions on its light receiving surface, and is driven by a drive signal from the CCD driver 42 to convert an object optical image exposed by each light receiving portion into an analog imaging signal and output it.

  The CCD driver 42 is driven by a synchronization pulse from the TG 43, and reads a through image signal from the CCD 38 when displaying a through image or calculating an appropriate exposure value, and reads out an image signal of a frame image from the CCD 38 at the time of shooting.

  The clock of the synchronization pulse generated by the TG 43 is an operation clock of the imaging unit 26, and as described above, it is 12 MHz in the power saving mode and 36 MHz in the power up mode. When the clock of the synchronization pulse input from the TG 43 to the CCD driver 42 is switched from 12 MHz to 36 MHz, the drive signal input from the CCD driver 42 to the CCD 38 is changed, and the imaging frame rate of the CCD 38 is switched from 30 fps to 60 fps. It is done.

  The imaging signal output from the CCD 38 is sent to the AFE 40. The AFE 40 includes a CDS circuit 40a, an AMP circuit 40b, and an A / D converter 40c, and operates in synchronization with the charge reading operation of the CCD 38 by receiving a synchronization pulse from the TG 43.

  The CDS circuit 40a removes noise from the imaging signal by performing correlated double sampling. The AMP circuit 40b amplifies the imaging signal with a gain corresponding to the imaging sensitivity set by the CPU 35. The A / D converter 40c converts the imaging signal from the AMP circuit 40b into digital image data.

  The control unit 27 includes a CPU 35, an image input controller 45, a digital image processing unit 46, a compression / decompression processing unit 47, an AF detection unit 48, an AE / AWB detection unit 49, a media controller 50, an internal memory 51, and an LCD driver 52. ing. These are controlled by the CPU 35 via the data bus 53 and can exchange data with each other.

  The CPU 35 controls each unit based on various signals from the shutter button 15, the power button 16, and the operation unit 18. To the CPU 35, a ROM 35a, a RAM 35b, and a strobe device 54 are connected. The strobe device 54 causes the strobe light emitting unit 14 to emit light in accordance with a command signal from the CPU 35.

  In the ROM 35a, programs for executing various sequences, programs corresponding to various program diagrams for determining combinations of shutter speeds, aperture values, and photographing sensitivities, and the like are written. To control. The RAM 35b is used as a work memory that temporarily stores data necessary for executing a shooting sequence or the like.

  The image input controller 45 controls input / output of image data to / from each unit via the data bus 53 in accordance with a control command from the CPU 35.

  The digital image processing unit 46 performs various image processing such as gradation conversion, white balance correction, and γ correction processing and YC conversion processing on the input image data.

  The AF detection unit 48 detects the contrast of the image being photographed using the image data output from the image input controller 45 for focusing the photographing lens 12, and sends the contrast information to the CPU 35. The CPU 35 refers to the contrast information and drives the focus mechanism of the photographing lens 12 via the motor driving unit 41 so that the contrast of the image being photographed is maximized.

  Based on the image data from the image input controller 45, the AE / AWB detection unit 49 detects the subject luminance and the type of the light source, and sends them to the CPU 35. The CPU 35 calculates the exposure value using the subject luminance from the AE / AWB detection unit 49. Further, the CPU 35 sets the white balance parameter of the digital image processing unit 46 based on the type of the light source.

  The CPU 35 converts the exposure value when displaying the through image into a combination of the aperture value, shutter speed, and shooting sensitivity according to the through image program, and the exposure value when shooting is determined according to the shooting program. Convert to a combination of

  The media controller 50 controls writing and reading of data in the memory card 55. The image data to be recorded is processed by the digital image processing unit 46 and the compression / decompression processing unit 47, sent to the media controller 50, and written to the memory card 55. At the time of reproduction, the image data recorded on the memory card 55 is read out by the media controller 50, sent to the compression / decompression processing unit 47 and decompressed, and then sent to the internal memory 51.

  The internal memory 51 is, for example, an SDRAM capable of high-speed reading and writing. The internal memory 51 is used for temporarily writing through image data to be displayed on the LCD 17 and frame image data to be recorded on the memory card 55.

  The LCD driver 52 reads the image data from the internal memory 51 in synchronization with the vertical synchronizing signal for reproduction during the through image display and the reproduction mode, and drives the LCD 17 based on the image data. As a result, the through image or the image read from the memory card 55 by the CCD 30 is displayed on the LCD 17.

  The operation of the digital camera 10 configured as described above will be described with reference to the flowcharts of FIGS. The secondary battery 20 is preloaded in the battery chamber of the camera body 11. When the power button 16 is pressed (st1), the CPU 35 sends a command signal to the switch circuit 29 of the power supply type determination unit 25 to turn on the switch circuit 29.

  When the plug 23a of the AC adapter 23 is inserted into the DC jack 22 (st2), the power from the AC adapter 23 is supplied to the power supply circuit 32, and the power adjusted by the power supply circuit 32 is supplied to each part of the digital camera 10. Supplied.

  The voltage detection circuit 31 detects the power supply voltage from the AC adapter 23 applied to the charge control circuit 30 and sends it to the CPU 35. The CPU 35 determines that the type of power supply is the AC adapter 23 and performs initial setting in the power-up mode (st3).

  In this initial setting, a command signal is sent from the CPU 35 to the TG 43, and as shown in the flowchart of FIG. 4, the clock of the synchronization pulse input from the TG 43 to the CCD driver 42 is set to 36 MHz (st11) and from the CCD 38. The vertical number of through image readout is set to 320 (st12), and the imaging frame rate of the CCD 38 is set to 60 fps (st13). At the same time, the brightness of the backlight of the LCD 17 is shifted to a higher luminance side, and the power supply auto-off operation of the LCD 17 is not performed.

  A through image pickup signal read from the CCD 38 is input to the AFE 40 and converted into digital image data. This image data is temporarily written in the internal memory 51 by the image input controller 45. Thereafter, the image data is read from the internal memory 51 and subjected to predetermined image processing by the digital image processing unit 46, and then sent to the LCD 17 via the LCD driver 52. Through the high resolution and smooth motion through. The image is displayed on the LCD 17.

  While the through image is displayed, AF control and AE control are performed by the AF detection unit 48, the AE / AWB detection unit 49, the motor drive unit 41, and the photographing lens 12 at regular time intervals.

  When the plug 23a of the AC adapter 23 is not inserted into the DC jack 22 (st2), the power from the secondary battery 20 is supplied to the power circuit 32, and the power adjusted by the power circuit 32 is supplied to each part of the digital camera 10. To be supplied.

  Since the measurement voltage A (v) input from the voltage detection circuit 31 is lower than the power supply voltage of the AC adapter, the CPU 35 determines that the power supply is the secondary battery 20, and the measurement voltage A (v) ≧ threshold voltage. It is determined whether or not α (v) is satisfied (st4).

  When A ≧ α, initial setting is performed in the same power-up mode as when the AC adapter 23 is connected (st3), and when A <α, initial setting is performed in the power saving mode (st5).

  In the initial setting in the power saving mode, as shown in FIG. 5, the operation clock of the imaging unit 26 is 12 MHz (st21), the vertical number of through image readout from the CCD 38 is 160 (st22), and the imaging frame rate is 30 fps (st23). ), Is set. In addition, the brightness of the backlight of the LCD 17 is set to be shifted to a lower luminance side, and the power supply auto-off of the LCD 17 is performed. Thereby, power saving of the digital camera 10 is achieved.

  In the above embodiment, the secondary battery is used as the power battery. However, an example of the power supply type determination unit using the primary battery will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same member as the said embodiment, and description is abbreviate | omitted. In the power supply type discriminating unit 60, a primary battery 61 is connected between the terminals 22 a and 22 b of the DC jack 22.

  One end of the primary battery 61 is connected to the power supply circuit 32 via the switch circuit 29. The other end of the primary battery 61 is connected to the power supply circuit 32 via the resistor 28. An intermediate terminal 62 between the other end of the primary battery 61 and the resistor 28 is connected to the voltage detection circuit 31. The voltage detection circuit 31 measures the voltage at the intermediate terminal 62 and inputs the result to the CPU 35.

  When the AC adapter 23 is not connected to the DC jack 22, since the terminals 22b and 22c are short-circuited, the other end of the primary battery 61 is grounded, and when the switch circuit 29 is turned on, the primary battery 61 Is supplied to the power supply circuit 32. At this time, since the intermediate terminal 62 is grounded, the measured voltage of the intermediate terminal 62 is substantially 0 (v) (Low), and this is input from the voltage detection circuit 31 to the CPU 35. Thereby, the CPU 35 determines that the power source is the primary battery 61.

  When the AC adapter 23 is connected to the DC jack 22, the short circuit between the terminals 22b and 22c is released. Therefore, when the switch circuit 29 is turned on, the power from the primary battery 61 is cut off, and instead from the AC adapter 23. Is supplied to the power supply circuit 32. Since the power supply voltage from the AC adapter 23 is applied to the intermediate terminal 62 via the resistor 28, the measured voltage of the intermediate terminal 62 becomes high (Hi), and this is input from the voltage detection circuit 31 to the CPU 35. As a result, the CPU 35 determines that the power source is the AC adapter 23.

  When a primary battery or a secondary battery is alternatively used as the power supply battery, for example, the charge control circuit 30 of the power supply type determination unit 25 shown in FIG. When the primary battery 61 is loaded instead of the secondary battery 20 of the power supply type discriminating unit 25, if the switch circuit 29 is in the off state, the primary battery 61 is charged when the AC adapter 23 is connected to the DC jack 22, Accidents such as rupture occur. However, at this time, when the CPU 35 determines that the power source is the primary battery 61 based on the measured voltage from the voltage detection circuit 31, the CPU 35 sends a control signal to the charge control circuit 30 to charge the charge control circuit 30. Is stopped, the primary battery 61 is prevented from being charged by mistake.

  In the embodiment described above, when the AC adapter is connected, the operation clock of the image pickup unit (especially the CCD), the vertical number of through images read from the CCD, and the frame rate are all increased. Without limitation, for example, two combinations (operation clock and vertical number, operation clock and frame rate, vertical number and frame rate) or only one may be increased.

  In the above-described embodiment, either 12 MHz in the power saving mode or 36 MHz in the power-up mode is selected as the operation clock of the imaging unit, but for recording (36 MHz (power-up mode)), At least three types of clocks for live view (18 MHz (normal mode)) and live view (12 MHz (power saving mode)) can be selected, and when an AC adapter is connected, (a) frame rate and vertical number In the A mode in which no change is made, the clock may be set in the normal mode, and (b) in the B mode in which the frame rate and / or the vertical number is not changed, the power-up mode may be set. In this case, the user switches between the A and B modes.

  In addition, at least two types of clocks for recording (36 MHz) and live view (12 MHz or 18 MHz) can be selected, and when recording of the AC adapter is detected and when the shutter button is pressed, These clocks may be selected.

  In addition, at least three types of clocks for recording (36 MHz), through image (18 MHz (normal mode)), and through image (12 MHz (power saving mode)) can be selected, and when an AC adapter is connected, (A) a C mode for a through image (normal mode) when acquiring a through image, and a C mode for a recording clock when the shutter button is pressed; (b) a D mode for a recording clock when acquiring a through image; May be switchable. In this case, the user switches between the C and D modes.

  Of course, the present invention is not limited to the numerical values such as clocks mentioned in the above embodiment.

It is a perspective view which shows the external appearance of the digital camera which implemented this invention. It is a block diagram which shows the electrical structure of a digital camera. It is a flowchart which shows the procedure of initial setting. It is a flowchart which shows the setting in power-up mode. It is a flowchart which shows the setting in a power saving mode. It is a block diagram which shows the example of another power supply type discrimination | determination part.

Explanation of symbols

10 Digital camera 17 LCD
DESCRIPTION OF SYMBOLS 20 Secondary battery 22 DC jack 23 AC adapter 25, 60 Power supply type discrimination | determination part 26 Imaging part 27 Control part 28 Resistor 29 Switch circuit 30 Charge control circuit 31 Voltage detection circuit 32 Power supply circuit 35 CPU
38 CCD
43 TG
61 Primary battery

Claims (7)

An image sensor that photoelectrically converts a subject image formed by a photographing optical system and outputs an image signal; and
A power source type discriminating unit for discriminating whether the power source is a battery or an AC adapter;
Control that increases the frame rate and / or the vertical number of the image pickup signal output from the image pickup device when the power supply type determination unit determines that the power supply is an AC adapter than when the power supply is a battery. A digital camera characterized by comprising:   The control unit increases an operation clock of the imaging device when the power source type determination unit determines that the power source is an AC adapter, compared to a case where the power source is a battery. 1. The digital camera according to 1.   When the power source type discriminating unit determines that the power source is an AC adapter, the control unit is configured to display a backlight of a liquid crystal display that displays an image based on the imaging signal, rather than when the power source is a battery. 3. The digital camera according to claim 1, wherein the brightness is increased.   The power source type discriminating unit discriminates whether the power source type is a primary battery, a secondary battery, or an AC adapter, and prohibits charging in the case of a primary battery, and uses a charging control circuit in the case of a secondary battery. The digital camera according to any one of claims 1 to 3, wherein charge control is managed respectively. A power source type determining step for determining whether the power source is a battery or an AC adapter;
A control step for increasing the frame rate and / or the vertical number of the imaging signal output from the imaging device when the power source is determined to be an AC adapter, compared to the case where the power source is a battery. And control method of digital camera.   The control step includes increasing the operation clock of the image sensor when the power source type determining unit determines that the power source is an AC adapter, compared to when the power source is a battery. The method of controlling a digital camera according to claim 5.   In the control step, when the power supply type determination unit determines that the power supply is an AC adapter, the luminance of the backlight of the liquid crystal display that displays an image based on the imaging signal is higher than that in the case where the power supply is a battery. The method for controlling a digital camera according to claim 5, further comprising increasing the height of the digital camera.

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